A study was conducted to detenmne the effect of lantana poisoning in eastern Ethiopia by the rnuse of clinical survey, que~tJonna!re survey and controlled experimental trial. For the chnical rnsurvey. infonnallon were collected through inten'lew, mspecting the clinical signs, gross and rnmicroscopic lesions. dlstnbution &: availability oflhc plant. rnAn overall elmica! prc"alence during the dry season was 16.7% and was found to be rn!Significantly higher 10 Haran Region (29.5%) compared to Babile district (8.7%). rnFurthermore. prevalence rlie (39.9~o) 10 Erer alley was significantly higher compared 10 rnother area (1.5%). Sex on the other hand seems to have no impact on the effect of lantana rnpoisoning in the study area The expenmental tnal involves tO artificially challenged rne'perimental groups. each nh ~t' en sheep and ten goats and matched control group >, ilhout rnexposurc. The trial demonmaled that lantana species prcvailing in the area are 10'IC 10 sheep rnand goat at a dose rale of 4ng kg hod) eight. rnCl1I1icai signs mamfested by e'penmentall~ mtoxlcated pOisoned sheep and goats mclude rndepreSSIOn, decrease appetite ... !J.:jC rumen. jaundice. photosensitization. and dehydration Ilh rnfirm dI)' feces and or diarrhea IIh deep yello color unne The chnical symptoms and post rnmonem lesions dJagnosed at field dunng clinical sun e) were quite similar to signs exhibited rnb~ experimentally intoxicated ~(,ats. The only eceptlon as secondary complication thai rnusually masks the pnmar;. ColU,.e m naturally mto,lcatcd goats. rnThis stud) has demonstrated th:11 lamana has been spread 109 and mfestlllg the asl area of rnt'astem highland From tht' sIud: area alone. aboul IO:!500 hectares of bush and shrub .. land rnere mfestcd. Hoccr. '101 Jl a .. pecl:i of lantana are harmful: II sencs a~ a sou ret: of rnfirewood. sen es a!o. mcolcÂ·1Jl r1:.;.nl. for cleanmg pla ... tlc C3ns. and to build fence .. around raml rnboundanes and encampments. rnIn any case. the haml''' Ihat 13r;t